First step is not beating yourself up when you can't seem to do a darn thing.
Second step is taking note of how you feel, whether it be angry, sad, irritable, excited, motivated, or even emotionless. After you've taken note of how your feeling, stop, and be sure not to dig too deep. Simply feel it out and recognize that much of what your feeling (if negative) may be your body telling you that it's working through something, or (if positive) that it's ready to take on something new, whether that be taking time for yourself, or diving into a new project; don't be afraid to give it your all.
Lastly, however you're feeling, be sure to give yourself plenty of positive reinforcements. Living with a chronic illness, or any kind of hardship, can cause a kind of imbalance that brings up emotions so strong you either want to run full speed towards them with the fear they may not last, or full speed away with the fear that they may never go away.